Apparatus and method for treating aqueous solutions and contaminants therein

ABSTRACT

The present disclosure is generally directed to devices and methods of treating aqueous solutions to help remove or otherwise reduce levels, concentrations or amounts of one or more contaminants. The present disclosure relates to an apparatus comprising spaced-apart electrode structural support members extending from a first sidewall to a second sidewall, the spaced-apart electrode structural support members each having at least one photoelectrode and counterelectrode coupled to respective terminals adapted to be electrically coupled to a power supply, and at least one ultraviolet light source between the spaced-apart electrode support members.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority as a continuation application to U.S.patent application Ser. No. 13/769,741 filed Feb. 18, 2013, which claimspriority as a continuation application to U.S. patent application Ser.No. 13/544,721 filed Jul. 9, 2012 now U.S. Pat. No. 8,398,828 issuedMar. 19, 2013, which claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/613,357 filed Mar. 20, 2012, and U.S.Provisional Patent Application Ser. No. 61/583,974 filed Jan. 6, 2012,the contents of which are hereby incorporated by reference in theirentirety.

BACKGROUND

Aqueous solutions often contain one or more contaminants. Such aqueoussolutions include, but are not limited to, hydraulic fracturing fluid,hydraulic fracturing backflow water, high-salinity solutions,groundwater, seawater, wastewater, drinking water, aquaculture (e.g.,aquarium water and aquaculture water) and ballast water. Furtherinformation of example aqueous solutions follows.

Hydraulic fracturing fluid includes any fluid or solution utilized tostimulate or produce gas or petroleum, or any such fluid or solutionafter it is used for that purpose.

Groundwater includes water that occurs below the surface of the Earth,where it occupies spaces in soils or geologic strata. Groundwater mayinclude water that supplies aquifers, wells and springs.

Wastewater may be any water that has been adversely affected in qualityby effects, processes, and/or materials derived from human or non-humanactivities. For example, wastewater may be water used for washing,flushing, or in a manufacturing process, that contains waste products.Wastewater may further be sewage that is contaminated by feces, urine,bodily fluids and/or other domestic, municipal or industrial liquidwaste products that is disposed of (e.g., via a pipe, sewer, or similarstructure or infrastructure or via a cesspool emptier). Wastewater mayoriginate from blackwater, cesspit leakage, septic tanks, sewagetreatment, washing water (also referred to as “graywater”), rainfall,groundwater infiltrated into sewage, surplus manufactured liquids, roaddrainage, industrial site drainage, and storm drains, for example.

Drinking water includes water intended for supply, for example, tohouseholds, commerce and/or industry. Drinking water may include waterdrawn directly from a tap or faucet. Drinking water may further includesources of drinking water supplies such as, for example, surface waterand groundwater.

Aquarium water includes, for example, freshwater, seawater, andsaltwater used in water-filled enclosures in which fish or other aquaticplants and animals are kept or intended to be kept. Aquarium water mayoriginate from aquariums of any size such as small home aquariums up tolarge aquariums (e.g., aquariums holding thousands to hundreds ofthousands of gallons of water).

Aquaculture water is water used in the cultivation of aquatic organisms.Aquaculture water includes, for example, freshwater, seawater, andsaltwater used in the cultivation of aquatic organisms.

Ballast water includes water, such as freshwater and seawater, held intanks and cargo holds of ships to increase the stability andmaneuverability during transit. Ballast water may also contain exoticspecies, alien species, invasive species, and/or nonindiginous speciesof organisms and plants, as well as sediments and contaminants.

A contaminant may be, for example, an organism, an organic chemical, aninorganic chemical, and/or combinations thereof. More specifically,“contaminant” may refer to any compound that is not naturally found inan aqueous solution. Contaminants may also include microorganisms thatmay be naturally found in an aqueous solution and may be considered safeat certain levels, but may present problems (e.g., disease and/or otherhealth problems) at different levels. In other cases (e.g., in the caseof ballast water), contaminants also include microorganisms that may benaturally found in the ballast water at its point of origin, but may beconsidered non-native or exotic species. Moreover, governmental agenciessuch as the United States Environmental Protection Agency, haveestablished standards for contaminants in water.

A contaminant may include a material commonly found in hydraulicfracturing fluid before or after use. For example, the contaminant maybe one or more of the following or combinations thereof: diluted acid(e.g., hydrochloric acid), a friction reducer (e.g., polyacrylamide), anantimicrobial agent (e.g. glutaraldehyde, ethanol, and/or methanol),scale inhibitor (e.g. ethylene glycol, alcohol, and sodium hydroxide),sodium and calcium salts, barium, oil, strontium, iron, heavy metals,soap, bacteria, etc. A contaminant may include a polymer to thicken orincrease viscosity to improve recovery of oil. A contaminant may alsoinclude guar or guar gum, which is commonly used as a thickening agentin many applications in oil recovery, the energy field, and the foodindustry.

A contaminant may be an organism or a microorganism. The microorganismmay be for example, a prokaryote, a eukaryote, and/or a virus. Theprokaryote may be, for example, pathogenic prokaryotes and fecalcoliform bacteria. Example prokaryotes may be Escherichia, Brucella,Legionella, sulfate reducing bacteria, acid producing bacteria, Cholerabacteria, and combinations thereof.

Example eukaryotes may be a protist, a fungus, or an algae. Exampleprotists (protozoans) may be Giardia, Cryptosporidium, and combinationsthereof. A eukaryote may also be a pathogenic eukaryote. Alsocontemplated within the disclosure are cysts of cyst-forming eukaryotessuch as, for example, Giardia.

A eukaryote may also include one or more disease vectors. A “diseasevector” refers any agent (person, animal or microorganism) that carriesand transmits an infectious pathogen into another living organism.Examples include, but are not limited to, an insect, nematode, or otherorganism that transmits an infectious agent. The life cycle of someinvertebrates such as, for example, insects, includes time spent inwater. Female mosquitoes, for example, lay their eggs in water. Otherinvertebrates such as, for example, nematodes, may deposit eggs inaqueous solutions. Cysts of invertebrates may also contaminate aqueousenvironments. Treatment of aqueous solutions in which a vector (e.g.,disease vector) may reside may thus serve as a control mechanism forboth the disease vector and the infectious agent.

A contaminant may be a virus. Example viruses may include a waterbornevirus such as, for example, enteric viruses, hepatitis A virus,hepatitis E virus, rotavirus, and MS2 coliphage, adenovirus, andnorovirus.

A contaminant may include an organic chemical. The organic chemical maybe any carbon-containing substance according to its ordinary meaning.The organic chemical may be, for example, chemical compounds,pharmaceuticals, over-the-counter drugs, dyes, agricultural pollutants,industrial pollutants, proteins, endocrine disruptors, fuel oxygenates,and/or personal care products. Examples of organic chemicals may includeacetone, acid blue 9, acid yellow 23, acrylamide, alachlor, atrazine,benzene, benzo(a)pyrene, bromodichloromethane, carbofuran, carbontetrachloride, chlorobenzene, chlorodane, chloroform, chloromethane,2,4-dichlorophenoxyacetic acid, dalapon, 1,2-dibromo-3-chloropropane,o-dichlorobenzene, p-dichlorobenzene, 1,2-dichloroethane,1,1-dichloroethylene, cis-1,2-dichloroethylene,trans-1,2-dichloroethylene, dichlormethane, 1,2-dichloropropane,di(2-ethylhexyl)adipate, di(2-ethylhexyl)phthalate, dinoseb, dioxin(2,3,7,8-TCDD), diquat, endothall, endrin, epichlorohydrin,ethylbenzene, ethylene dibromide, glyphosate, a haloacetic acid,heptachlor, heptachlor epoxide, hexachlorobenzene,hexachlorocyclopentadiene, lindane, methyl-tertiary-butyl ether,methyoxychlor, napthoxamyl (vydate), naphthalene, pentachlorophenol,phenol, picloram, isopropylbenzene, N-butylbenzene, N-propylbenzene,Sec-butylbenzene, polychlorinated biphenyls (PCBs), simazine, sodiumphenoxyacetic acid, styrene, tetrachloroethylene, toluene, toxaphene,2,4,5-TP (silvex), 1,2,4-trichlorobenzene, 1,1,1-trichloroethane,1,1,2-trichloroethane, trichloroethylene, a trihalomethane,1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, vinyl chloride,o-xylene, m-xylene, p-xylene, an endocrine disruptor, a G-series nerveagent, a V-series nerve agent, bisphenol-A, bovine serum albumin,carbamazepine, cortisol, estradiol-17β, gasoline, gelbstoff, triclosan,ricin, a polybrominated diphenyl ether, a polychlorinated diphenylether, and a polychlorinated biphenyl. Methyl tert-butyl ether (alsoknown as, methyl tertiary-butyl ether) is a particularly applicableorganic chemical contaminant.

A contaminant may include an inorganic chemical. More specifically, thecontaminant may be a nitrogen-containing inorganic chemical such as, forexample, ammonia (NH₃) or ammonium (NH₄). Contaminants may includenon-nitrogen-containing inorganic chemicals such as, for example,aluminum, antimony, arsenic, asbestos, barium, beryllium, bromate,cadmium, chloramine, chlorine, chlorine dioxide, chlorite, chromium,copper, cyanide, fluoride, iron, lead, manganese, mercury, nickel,nitrate, nitrite, selenium, silver, sodium, sulfate, thallium, and/orzinc.

A contaminant may include a radionuclide. Radioactive contamination maybe the result of a spill or accident during the production or use ofradionuclides (radioisotopes). Example radionuclides include, but arenot limited to, an alpha photon emitter, a beta photon emitter, radium226, radium 228, and uranium.

Various methods exist for handling contaminants and contaminated aqueoussolutions. Generally, for example, contaminants may be contained toprevent them from migrating from their source, removed, and immobilizedor detoxified.

Another method for handling contaminants and contaminated aqueoussolutions is to treat the aqueous solution at its point-of-use.Point-of-use water treatment refers to a variety of different watertreatment methods (physical, chemical and biological) for improvingwater quality for an intended use such as, for example, drinking,bathing, washing, irrigation, etc., at the point of consumption insteadof at a centralized location. Point-of-use treatment may include watertreatment at a more decentralized level such as a small community or ata household. A drastic alternative is to abandon use of the contaminatedaqueous solutions and use an alternative source.

Other methods for handling contaminants and contaminated aqueoussolutions are used for removing gasoline and fuel contaminants, andparticularly the gasoline additive, MTBE. These methods include, forexample, phytoremediation, soil vapor extraction, multiphase extraction,air sparging, membranes (reverse osmosis), and other technologies. Inaddition to high cost, some of these alternative remediationtechnologies result in the formation of other contaminants atconcentrations higher than their recommended limits. For example, mostoxidation methods of MTBE result in the formation of bromate ions higherthan its recommended limit of 10 μg/L in drinking water (Liang et al.,“Oxidation of MTBE by ozone and peroxone processes,” J. Am. Water WorksAssoc. 91:104 (1999)).

A number of technologies have proven useful in reducing MTBEcontamination, including photocatalytic degradation with UV light andtitanium dioxide (Barreto et al., “Photocatalytic degradation of methyltert-butyl ether in TiO₂ slurries: a proposed reaction scheme,” WaterRes. 29:1243-1248 (1995); Cater et al., UV/H₂O₂ treatment of MTBE incontaminated water,” Environ. Sci Technol. 34:659 (2000)), oxidationwith UV and hydrogen peroxide (Chang and Young, “Kinetics of MTBEdegradation and by-product formation during UV/hydrogen peroxide watertreatment,” Water Res. 34:2223 (2000); Stefan et al., Degradationpathways during the treatment of MTBE by the UV/H₂O₂ process,” Environ.Sci. Technol. 34:650 (2000)), oxidation by ozone and peroxone (Liang etal., “Oxidation of MTBE by ozone and peroxone processes,” J. Am. WaterWorks Assoc. 91:104 (1999)) and in situ and ex situ bioremediation(Bradley et al., “Aerobic mineralization of MTBE and tert-Butyl alcoholby stream bed sediment microorganisms,” Environ. Sci. Technol.33:1877-1879 (1999)).

Use of titanium dioxide (titania, TiO₂) as a photocatalyst has beenshown to degrade a wide range of organic pollutants in water, includinghalogenated and aromatic hydrocarbons, nitrogen-containing heterocycliccompounds, hydrogen sulfide, surfactants, herbicides, and metalcomplexes (Matthews, “Photo-oxidation of organic material in aqueoussuspensions of titanium dioxide,” Water Res. 220:569 (1986); Matthews,“Kinetic of photocatalytic oxidation of organic solutions overtitanium-dioxide,” J. Catal. 113:549 (1987); Ollis et al., “Destructionof water contaminants,” Environ. Sci. Technol. 25:1522 (1991)).

Irradiation of a semiconductor photocatalyst, such as titanium dioxide(TiO₂), zinc oxide, or cadmium sulfide, with light energy equal to orgreater than the band gap energy (Ebg) causes electrons to shift fromthe valence band to the conduction band. If the ambient and surfaceconditions are correct, the excited electron and hole pair canparticipate in oxidation-reduction reactions. The oxygen acts as anelectron acceptor and forms hydrogen peroxide. The electron donors(i.e., contaminants) are oxidized either directly by valence band holesor indirectly by hydroxyl radicals (Hoffman et al., “Photocatalyticproduction of H₂O₂ and organic peroxide on quantum-sized semi-conductorcolloids,” Environ. Sci. Technol. 28:776 (1994)). Additionally, etherscan be degraded oxidatively using a photocatalyst such as TiO₂ (Lichtinet al., “Photopromoted titanium oxide-catalyzed oxidative decompositionof organic pollutants in water and in the vapor phase,” Water Pollut.Res. J. Can. 27:203 (1992)). A reaction scheme for photocatalyticallydestroying MTBE using UV and TiO₂ has been proposed, butphotodegradation took place only in the presence of catalyst, oxygen,and near UV irradiation and MTBE was converted to several intermediates(tertiary-butyl formate, tertiary-butyl alcohol, acetone, andalpha-hydroperoxy MTBE) before complete mineralization (Barreto et al.“Photocatalytic degradation of methyl tert-butyl ether in TiO₂ slurries:a proposed reaction scheme,” Water Res. 29:1243-1248 (1995)).

A more commonly used method of treating aqueous solutions fordisinfection of microorganisms is chemically treating the solution withchlorine. Disinfection with chlorine, however, has severaldisadvantages. For example, chlorine content must be regularlymonitored, formation of undesirable carcinogenic by-products may occur,chlorine has an unpleasant odor and taste, and chlorine requires thestorage of water in a holding tank for a specific time period.

Aqueous solutions used for hydraulically fracturing gas wells (e.g.,fracturing or frac fluids) or otherwise stimulating petroleum, oiland/or gas production also require treatment. Such solutions or fracfluids typically include one or more components or contaminantsincluding, by way of example and without limitation, water, sand,diluted acid (e.g., hydrochloric acid), one or more polymers or frictionreducers (e.g., polyacrylamide), one or more antimicrobial agents (e.g.glutaraldehyde, ethanol, and/or methanol), one or more scale inhibitors(e.g. ethylene glycol, alcohol, and sodium hydroxide), and one or morethickening agents (e.g., guar). In addition, a significant percentage ofsuch solutions and fluids return toward the Earth surface as flowback,and later as produced water, after they have been injected into ahydrofrac zone underground. As they return toward the Earth surface, thesolutions and fluids also pick up other contaminants from the earth suchas salt (e.g., sodium and calcium salts). Such fluids may also includebarium, oil, strontium, iron, heavy metals, soap, high concentrations ofbacteria including acid producing and sulfate reducing bacteria, etc.

Aqueous solutions used for hydraulically fracturing gas wells orotherwise stimulating oil and gas production are difficult and expensiveto treat for many reasons including, without limitation, the salinity ofthe solutions. For that reason, such fluids are often ultimatelydisposed of underground, offsite, or into natural water bodies. In somecases, certain states and countries will not allow fracking due toremediation concerns.

Accordingly, there is a need in the art for alternative approaches fortreating aqueous solutions to remove and/or reduce amounts ofcontaminants. Specifically, it would be advantageous to have apparatusand/or methods for treating various aqueous solutions includinghydraulic fracturing fluid, hydraulic fracturing backflow water,high-salinity water, groundwater, seawater, wastewater, drinking water,aquarium water, and aquaculture water, and/or for preparation ofultrapure water for laboratory use and remediation of textile industrydye waste water, among others, that help remove or eliminatecontaminants without the addition of chemical constituents, theproduction of potentially hazardous by-products, or the need forlong-term storage.

SUMMARY

The present disclosure is generally directed to devices and methods oftreating aqueous solutions to help remove or otherwise reduce levels oramounts of one or more contaminants. More specifically, the presentdisclosure relates to an apparatus for removing or reducing the level ofcontaminants in a solution comprising: a container having an inner boxprovided therein; the inner box comprising a first sidewall and a secondsidewall, and an inner box cover and spaced-apart electrode structuralsupport members extending from the first sidewall to the secondsidewall; the inner box cover defining apertures with sleeves providedtherein that extend into a space between the spaced-apart electrodestructural support members; the spaced-apart electrode structuralsupport members each having a photoelectrode and counterelectrodeprovided thereon with a separator provided between the photoelectrodeand counterelectrode; wherein the photoelectrode comprises a primarilytitanium foil support with a layer of titanium dioxide provided thereon;and wherein the photoelectrode and counterelectrode are each coupled toa respective terminal adapted to be electrically coupled to a powersupply.

The present disclosure further relates to a n apparatus for removing orreducing the level of contaminants in a solution comprising a containerhaving an inner structure provided therein; the inner structurecomprising a sidewall, and an inner structure cover and spaced-apartelectrode structural support members extending from the sidewall to forma cell between the spaced-apart electrode structural support members;the inner structure cover defining apertures with sleeves providedtherein that extend at least from the inner structure cover to a bottomof the cell formed between the spaced-apart electrode structural supportmembers; the spaced-apart electrode structural support members eachhaving a photoelectrode and counterelectrode provided thereon with aseparator provided between the photoelectrode and counterelectrode;wherein the photoelectrode comprises a primarily titanium foil supportwith a layer of titanium dioxide provided thereon; and wherein thephotoelectrode and counterelectrode are each coupled to a terminaladapted to be electrically coupled to a power supply.

The present invention also relates to an apparatus for removing orreducing the level of contaminants in a solution comprising a containerhaving an inner structure provided therein; the inner structurecomprising a first set of opposing members coupled to a second set ofopposing members, and spaced-apart electrode structural support membersextending between the first and second set of opposing members; thespaced-apart electrode structural support members each having aphotoelectrode and counterelectrode provided thereon with a separatorprovided between the photoelectrode and counterelectrode; wherein thefirst set of opposing members define apertures with sleeves providedtherein, which sleeves extend at least from one opposing member of thefirst set of opposing structure members to another opposing member ofthe first set of opposing members into a space between the spaced-apartelectrode structural support members; wherein the photoelectrodecomprises a primarily titanium foil support with a layer of titaniumdioxide provided thereon; and wherein the photoelectrode andcounterelectrode are each coupled to a terminal adapted to beelectrically coupled to a power supply.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be better understood, and features, aspects andadvantages other than those set forth above will become apparent whenconsideration is given to the following detailed description thereof.Such detailed description makes reference to the following drawings,wherein:

FIG. 1 is a partially broken front view of a PECO system including aPECO device, according to one or more examples of embodiments.

FIG. 2 is a front view of a PECO system including a PECO device,according to one or more examples of embodiments.

FIG. 3 is a side view of the PECO system illustrated in FIG. 2,according to one or more examples of embodiments.

FIG. 4 is an isometric view of a panel of a PECO system, according toone or more examples of embodiments.

FIG. 5 is an isometric view of a PECO device, which may also be referredto as a photoelectrocatalytic cell, according to one or more examples ofembodiments.

FIG. 6 is a top view of the PECO device illustrated in FIG. 5 accordingto one or more examples of embodiments.

FIG. 7 is an end view of the PECO device illustrated in FIG. 5 accordingto one or more examples of embodiments.

FIG. 8 is a front view of the PECO device illustrated in FIG. 5according to one or more examples of embodiments.

FIG. 9 is a sectional view of the PECO device illustrated in FIG. 8according to one or more examples of embodiments.

FIG. 10 is an isometric view of an inner box or structure of a PECOdevice, according to one or more examples of embodiments.

FIG. 11 is a partially broken isometric view of the inner box or systemof a PECO device illustrated in FIG. 10, according to one or moreexamples of embodiments.

FIG. 12 is an end view of the inner box or structure of a PECO deviceillustrated in FIG. 10, according to one or more examples ofembodiments.

FIG. 13 is a sectional view of the inner box or system of a PECO deviceillustrated in FIG. 12, according to one or more examples ofembodiments.

FIG. 14 is a sectional view of the inner box or structure of a PECOdevice illustrated in FIG. 13, according to one or more examples ofembodiments.

FIG. 15 is a top view of an inner box or structure of a PECO device,according to one or more examples of embodiments.

FIG. 16 is a partially broken view of an electrode structural supportmember including a photoelectrode, counterelectrode and separator of theinner box or structure of a PECO device, according to one or moreexamples of embodiments.

FIG. 17 is a fragmentary view of an inner box or structure of a PECOdevice according to one or more examples of embodiments.

While the disclosure is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and are herein described below in detail. Forexample, any numbers, measurements, and/or dimensions illustrated in theFigures are for purposes of example only. Any number, measurement ordimension suitable for the purposes provided herein may be acceptable.It should be understood that the description of specific embodiments isnot intended to limit the disclosure from covering all modifications,equivalents and alternatives falling within the spirit and scope of thedisclosure.

DETAILED DESCRIPTION

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which the disclosure belongs. Although any methods andmaterials similar to or equivalent to those described herein may be usedin the practice or testing of the present disclosure, example methodsand materials are described below.

Various embodiments of a photoelectric catalytic oxidation (PECO) systemand device are described. In various embodiments, the PECO deviceincludes and/or is provided in an apparatus or reactor or substantiallyself-contained device. The reactor in various embodiments includes acontainer which is adapted to receive components (e.g. operativecomponents) of the PECO device and/or receive, contain and/or circulatefluid or aqueous solution. In various embodiments, the container housesa plurality of counterelectrodes (e.g. cathodes) and photoelectrodes(e.g. anodes) provided or arranged on structural supports spaced onopposing sides of UV light sources and forming a series of cells. Invarious embodiments, the plurality of counterelectrodes (e.g. cathodes),photoelectrodes (e.g. anodes), corresponding supports, and UV lightsources may be provided in an inner structure or box received within thecontainer. In various embodiments, flow of fluid or solution isfacilitated in a serpentine or undulating pattern through the series ofcells. In various embodiments, one or more a power supplies and/orballasts are included or provided for powering the UV-light sourcesand/or for providing electrical potential to one or more of thecounterelectrodes (e.g., cathodes) and photoelectrodes (e.g., anodes).In various embodiments, one or more power supplies and/or ballasts areelectrically coupled to UV-light sources and/or electrodes but providedexternally to the container.

Generally, in various embodiments, a method for reducing the level oramount of one or more contaminants in solution or fluid describedincludes introducing the solution into a housing or container or cellincluding: a UV light; a photoelectrode (e.g., anode), wherein thephotoelectrode comprises an anatase polymorph of titanium, a rutilepolymorph of titanium, or a nanoporous film of titanium dioxide; and acounterelectrode (e.g., cathode). In various embodiments, thephotoelectrode is irradiated with UV light, and a first potential isapplied to the photoelectrode and counterelectrode for a first period oftime. In various embodiments, a second potential is applied to thephotoelectrode and counterelectrode for a second period of time. As aresult, in various embodiments, the contaminant level or amount insolution is reduced.

Referring to FIGS. 1-3, a PECO system 100 according to variousembodiments is shown. In various embodiments, PECO system 100 includes aPECO unit, device, assembly or apparatus 110, and a panel 120. Invarious embodiments, components within panel 120 and components withinPECO unit are electrically coupled. In various embodiments, and as shownin the Figures, PECO system 100 includes multiple PECO units, devices,assemblies or apparatus 110, components of which are electricallycoupled to components provided in at least one panel 120.Explosion-proof or resistant fittings or couplings 130 may be utilizedin connection with PECO units 110 and panel 120 to help prevent certainmaterials (e.g., ignitable or flammable gases or vapors) in PECO unit110 from reaching or otherwise reacting with a component external toPECO unit 110 (e.g., a component within panel 120, a power source, aballast, etc.). In examples of embodiments, various PECO units, devices,assemblies or apparatus 110 are in operative communication (e.g., anoutlet or out-flow connection of a first PECO unit, device, assembly orapparatus is coupled (e.g., operatively coupled) to an inlet or in-flowconnection of a second PECO unit, device, assembly or apparatus.

As shown in FIGS. 1-4, in various embodiments, PECO system 100 includespanel 120. In various embodiments, panel 120 may house variouscomponents of PECO system. For example, in various embodiments, panel120 houses one or more power supplies. In various embodiments, panel 120houses one or more controls, circuits or switches which may be utilizedto operate PECO system 100 and its components. In various embodiments,panel 120 includes one or more circuits (e.g., an H circuit), switches(e.g., a MOSFET) or other devices for reversing the potential or biasacross a photoelectrode and/or counterelectrode. In various embodiments,panel 120 includes a door or other component or aperture for ease ofaccessing components housed within panel 120. The panel may be providedwith locks and/or handles or other hardware.

In various embodiments, panel 120 includes or defines one or moreapertures. For example, one or more apertures may be defined by and/orprovided through panel 120 to allow internal components of panel 120 tobe electrically coupled to one or more components provided internally toa PECO unit or in another panel or enclosure (e.g. an electricalenclosure housing ballasts). For example, and as shown in FIG. 4, invarious embodiments, a wall of panel 120 includes or defines at leastone aperture through which wiring is or may be provided for electricallycoupling electrodes within a PECO unit to one or more power supplies inpanel 120. In various embodiments, the circuits, switches or other suchdevices are housed in the panel and electrically connected or coupled tocomponents of the PECO unit (e.g. a photoelectrode, counterelectrodeand/or terminals) or other PECO system 100 components (e.g. ballasts).As shown in FIG. 4, various fittings (e.g., explosion-proof or resistantfittings) 130 are provided in or about one or more of the aperturesdefined by panel 120 to help prevent certain materials (e.g., ignitableor flammable gases or vapors) from reaching or otherwise reacting withcomponents within panel 120.

As shown in the Figures, apart from any electrical connection and thelike, panel 10 is mounted or otherwise provided separately from PECOunit 110. As also shown, in various embodiments, one or more componentsof panel 120 are electrically coupled to components of multiple PECOunits 110. It should be appreciated, however, that the panel may becoupled to PECO unit 110 or the container therefor, and components ofthe panel may be electrically coupled to a single PECO unit 110 oradditional units.

As shown in FIGS. 5-9, in various embodiments, PECO unit, device,assembly or apparatus 110 includes a container or housing 140 formed bya plurality of adjoined sidewalls coupled to a bottom. Container 140 invarious embodiments (e.g., in the illustrated examples) forms acontainer cavity with an opening at the top to allow or provide accessinto the container cavity and to various PECO system 100 and/or PECOunit 110 components. It is contemplated that access openings or otheropenings may be provided, or also provided, elsewhere (e.g., on thecontainer sidewalls or bottom).

Container 140 may be formed of any suitable material and be of any sizeand/or shape suitable for its intended purposes. In various embodiments,container 140 preferably includes, or is provided with, tight seals,including upon engagement with a cover or lid 160. Further, thecontainer may be pressurized (e.g, under negative pressure) and/orexplosion-proof or resistant. While specific examples are provided,alternative materials and sizes suitable for the purposes of the PECOdevice are acceptable.

The container may be provided with locks and/or handles or otherhardware. In various embodiments, container 140 includes or defines oneor more in-flow and/or out-flow apertures, fittings or connections. Forexample, a first aperture may be defined by and/or provided through oneor more sidewalls, the lid, or the bottom, for connection to a fluidsupply source or for connection to a waste-line or out-flow connection.In one or more examples of embodiments, the fluid supply source and/orthe waste-line or out-flow may be a conduit, hose, tube or pipe or othercommercially available device used for transporting a fluid. In variousembodiments, a suitable coupling or fitting 150 may be provided in anaperture defined in container 140, and/or otherwise coupled or attachedto container 140 (e.g. for mating with the supply source or waste-lineor out-flow connection and providing a tight seal for PECO device 110).

In various embodiments, container 140 also includes a container cover,top, or lid 160 sized and/or shaped to cover the opening at the top ofthe container cavity. Lid 160 may be entirely separable from container140 and/or partially separable. Container cover or lid 160 may becoupled to the container by one or more hinges, or may be formed by aliving hinge or plastic hinge with the container. In variousembodiments, container cover or lid 160 defines or includes one or moreapertures for passage of an electrical connection, wire, cable or otherdesirable component.

Referring to FIG. 6, in various embodiments, container cover or lid 160includes multiple members or components. As shown in FIG. 6, in variousembodiments, container cover or lid 160 includes a frame member 170 andan access cover or lid 180. In various embodiments, container cover 160includes an electrical cover or lid 190. In various embodiments, framemember 170 defines an aperture or opening that may be utilized to accesscomponents of PECO unit 110 (e.g., UV bulbs), wiring, connections, etc.,without having to uncouple or remove container cover or lid 160 in itsentirety. In various embodiments, access cover 180 is sized and/orshaped to cover the aperture or opening defined by frame member 170. Asshown in FIG. 6, in various embodiments, access cover 180 is sizedand/or shaped to overlap a portion of frame member 170 (e.g., a lip offrame member 170 helping define the aperture or opening defined by framemember 170). In various embodiments, access cover 180 is removablycoupled or fastened to frame member 170.

In various embodiments, access cover 180 defines an aperture or openingthat may be utilized to access components of PECO unit 110 (e.g.,electrical connections) without having to uncouple or remove entirecontainer cover or lid 160, or entire access cover or lid 180. Invarious embodiments, electrical cover or lid 190 is sized and/or shapedto cover the opening defined by access cover 180. As shown in FIG. 6, invarious embodiments, electrical cover or lid 190 is sized and/or shapedto overlap a portion of access cover 180 (e.g., a lip of access cover180 defining the opening). In various embodiments, electrical cover 190or lid may be removably coupled to access cover 180.

In various embodiments, container cover or lid 160 (e.g., frame member170 and/or electrical cover 190) includes or defines one or moreapertures. For example, one or more apertures may be defined by and/orprovided through container cover 160 to allow internal components ofPECO unit 110 to be electrically coupled to components outside PECO unit110 (e.g. one or more power supplies and/or ballasts provided externallyto container 140). For example, and as shown in FIG. 6, in variousembodiments, cover or lid 160 (e.g., frame member 170) includes ordefines at least one first aperture 200 through which wiring is or maybe provided for electrically coupling UV bulbs within container 140 orto ballasts outside container 140. As another example, and as shown inFIG. 6, cover or lid 160 (e.g., electrical cover 190) includes ordefines at least one second aperture 210 through which wiring is or maybe provided for electrically coupling electrodes within container 140 orballasts to one or more power supplies. Referring again to FIG. 6,various fittings (e.g., explosion-proof or resistant fittings) may beprovided in or about one or more of the apertures defined by containercover 160 to help prevent certain materials (e.g., ignitable orflammable gases or vapors) from reaching or otherwise reacting with acomponent external to PECO unit 110 (e.g., components within the panel,a power source, a ballast, etc.)

In various embodiments, removal of electrical cover 190 allows access toconnections (e.g. main connections) fastener panel 120 and PECO unit 110such that various such connections may be disconnected to allow a PECOunit 110 to be replaced with another PECO unit to allow servicing ofPECO unit 110 while minimizing PECO system 100 down-time or otherwiseoptimizing PECO system 100 maintenance.

Referring to FIGS. 5 and 7, container 140 may include or be providedwithin a support structure or frame 220. In various embodiments, supportstructure 220 is welded to the exterior of container 140. However, thesupport structure may be coupled or fastened, or removably coupled orfastened, to the container in a variety of other ways including, by wayof example, through the use of bolts, other fasteners, adhesives, etc.The support structure may also be provided around the container withoutbeing affixed to the container.

In various embodiments, PECO system 100 or PECO unit 110 includes anelectrical enclosure 230. Referring to FIGS. 5-8, in variousembodiments, electrical enclosure 230 is provided external to container140. In various embodiments, electrical enclosure 230 is coupled ormounted to container 140 (e.g., to a side of container 140). However,the electrical enclosure may be removably coupled or otherwiseunattached to the container, apart from components housed within theelectrical enclosure which, in various embodiments, are electricallycoupled to one or more components housed within the container.

In various embodiments, electrical enclosure 230 (e.g., a side and/ortop of electrical enclosure 230) includes or defines one or moreapertures 240. For example, in various embodiments, one or moreapertures 240 are provided through the top of electrical enclosure 230to allow components of PECO unit 110 inside container 140 to beelectrically coupled to one or more components (e.g. power suppliesand/or ballasts) provided within electrical enclosure 230. For example,and as shown in FIGS. 5-8, in various embodiments, electrical enclosure230 includes or defines multiple apertures through which wiring may passor be provided for electrically coupling UV bulbs within container 140to ballasts provided in electrical enclosure 230. In variousembodiments, various fittings (e.g., explosion-proof or explosionresistant fittings) may be provided in or about the apertures defined byelectrical enclosure 230 to help prevent certain materials (e.g.,ignitable or flammable gases or vapors) from reaching or otherwisereacting with a component external to PECO unit 110 (e.g., a ballast orother component provided in electrical enclosure 230, etc.).

Further, in one or more examples of embodiments, electrical enclosure230 is explosion proof or resistant. For example, the PECO system orunit may utilize a sealed electrical enclosure 230 to house electricalcontrols, which enclosure may be purged and/or pressurized to allow usein hazardous atmospheres. One suitable example of such a purged andpressurized atmosphere is per National Fire Protection Association(NFPA) standard 496 relating to enclosures for electrical equipment.

Referring to FIG. 9, in various embodiments, the cavity of container 140may be compartmentalized or may have one or more segments. In one ormore examples of embodiments, the cavity of container 140 receives orcarries a variety of components and/or structures. Various componentsmay be provided in an inner structure or box provided in the cavity ofcontainer 140. However, it is also contemplated that the variouscomponents may be provided in the container without an inner box orstructure.

An inner structure or box 300, in various embodiments and as shown inFIGS. 10-14, includes and/or is formed by a plurality of adjoined wallsor sidewalls connected to a base or bottom, or to the container'sbottom, forming an inner box cavity. The inner structure or box may beformed of any material and of any size and/or shape suitable for itsintended purposes. For example, the inner structure or box may be amolded, high-durability plastic or polyethylene and may be formed to beresistant to one or more contaminants. As can be seen by reference tothe Figures, in various embodiments, the inner structure or box is sizedand/or shaped to fit within the container (e.g., the container'scavity), and may further be sized to be smaller than the width, lengthor diameter of the container's cavity such that one or more spaces existor are formed between the inner structure or box walls or sidewalls andthe container walls or sidewalls. The spaces between the inner structureor box walls or sidewalls may provide areas for the containment and/orflow of a solution or fluid, or other PECO unit and/or systemcomponents.

In various embodiments, the inner box is sized to leave space betweenthe top of the inner box and the container cover or lid, and wiring maybe provided in that space. In various embodiments, one or more seals areprovided between the container and inner box such that the space betweenthe top of the inner box and the container lid or cover is sealed fromspaces or areas where fluid is provided, flows or is contained. Invarious embodiments, the space between the top of the inner structureand the container cover or lid is purged and/or pressured to help makethe space more explosion-proof or resistant.

As shown in FIG. 10, at least one wall or sidewall of the innerstructure or box defines one or more apertures or weir channels 310about the top of the sidewall. The apertures or weir channels defined inthe sidewall of the inner box or structure may help control the heightof solution or fluid provided in the inner structure or box. In variousembodiments, at least one wall or sidewall of the inner structure or boxdiscloses one or more features (e.g. ridges or channels) for helping addstability and structure to inner structure box. For example, walls mayinclude grooves to receive a portion (e.g. an edge) of electrodestructure support members 370.

As shown in FIGS. 10-14, in various embodiments, a baffle cavity 330 isprovided near a sidewall of inner structure 300. In various embodiments,baffle cavity 330 is formed by a plurality of adjoined baffle sidewalls350 connected or coupled to an electrode structural support member 370about a plurality of spaced holes or apertures 320 defined by electrodestructural support member 370. In various embodiments, the adjoinedbaffle sidewalls 350 are connected or coupled to a base or bottom, or tothe bottom of inner box or structure 300, or to the bottom of thecontainer to help form the baffle cavity. In various embodiments, abaffle sidewall 350 defines includes or defines an aperture 340. Invarious embodiments, aperture 340 is utilized to introduce fluid orsolution into baffle cavity 330. In various embodiments, a fitting orcoupling is provided in aperture 340 and, as shown in FIGS. 10 and 14,may be utilized to operatively couple a pump 360 to baffle cavity 330.

More specifically, in various embodiments, pump 360 or more than onepump may optionally be provided (see FIGS. 10 and 14) to help introducefluid or solution into baffle cavity 330. Pump 360 may also be used, forexample, to help introduce fluid or solution into the inner box orstructure, for circulation or recirculation, etc.

One or more apertures may be provided in the sidewalls, and/or bottom ofthe inner structure or box. The aperture(s) may be adapted to receive afitting, such as for connection to a pipe, tube or other plumbing forthe transfer of fluid into or out of the inner box.

Referring to FIGS. 11-14, inner structure or box 300 includes, receives,or carries one or more electrode structural support members 370. Invarious embodiments, multiple electrode structural support members 370are spaced apart in inner box or structure 300. In one or more examplesof embodiments, each electrode structural support member 370 is sized tospan the width of inner box 300. However, one or more electrodestructural support members may extend less than the full width of innerbox 300 or inner box cavity. In various embodiments, one or moreelectrode structural members 370 are sized to extend the depth of innerbox 300 or inner box cavity, or a portion thereof.

In various embodiments, one or more apertures 380 are defined by andspaced apart proximate to a side or outer edge of electrode structuralsupport members 370. In particular, in the illustrated examples,apertures 380 are spaced apart between the top and bottom of electrodestructural support member 370 near an edge of electrode structuralsupport member 370. When electrode structural support members 370 areprovided in or otherwise in position in inner box 300, apertures 380permit fluid flow through structural support member 370 and betweenadjacent cavities or cells 390 formed between respective electrodestructural support members 370 and electrodes (see arrow 395 on FIG. 15for an example serpentine, sinuous or winding flow pattern). In variousembodiments and as shown in FIG. 11, apertures 380 also permit thepassage of fluid or solution into, through, or out of inner box 300 onan approximate side portion of inner box 300.

Depending upon the application or desired flow rate, apertures 380 ofelectrode structural support members may be sized larger, smaller,relatively differently, etc. Further, apertures 380 allow flow even whenelectrode structural support members 370 extend full width of inner box300, or the inner box cavity.

In one or more examples of embodiments, the apparatus is provided with afluid flow path that facilitates or operates as a venturi system. Inother words, in various embodiments, the cross-sectional area of thefluid flow path is adjusted to control the velocity of the fluid (whichincreases as the cross sectional area decreases), and the staticpressure (which correspondingly decreases with cross-sectional areadecrease). As a result, in examples of embodiments, less standing fluid,(e.g. water) is required for the system to operate.

As can be seen in FIG. 11, in various embodiments, a plurality ofelectrode structural support members 370 are provided, arranged orpositioned in inner box or structure 300 in an alternating pattern suchthat adjacent electrode structural support members 370 are provided withapertures 380 which are not aligned, and more preferably on, proximateto or adjacent opposite edges or sides (e.g. in a mirror image pattern),such that fluid or solution may flow through the respective aperturesand/or inner box 300 in a serpentine or undulating pattern.

In this arrangement according to various embodiments, respectiveelectrodes and terminals (as will be described in greater detail below)on adjacent electrode structural support members 370 are also offsetfrom one another, alternating in being spaced from opposite sides ofinner box 300. Further, adjacent electrode structural support members370 (and facing photoelectrodes as discussed in greater detail below)form a cavity or cell 390 therebetween. In various embodiments, theplurality of electrode structural support members 370 in inner box 300helps form a plurality of cells 390 (e.g. inter-connected cells)operatively or otherwise connected in series by apertures 380 inelectrode structural support members 370.

One or more or the electrode structural support members may includemultiple joined segments or portions. In various embodiments, theelectrodes are supported on a first segment or portion of the electrodestructural support member, which portion is coupled to an adjacentsegment or portion defining or having a plurality of apertures. Invarious embodiments, one or more electrode structural support members370 are a single piece of material or layers of material(s).

Referring to FIG. 13, in various embodiments, inner box or structure 300includes a bottom or partition to promote flow from inlet to outlet. Invarious embodiments, a “false” bottom or other lower partition isprovided near the bottom of at least a portion of inner box or structure300 such that the bottom of inner box 300 near the inlet is relativelyhigher than bottom of inner box near the outlet.

Referring to FIG. 15, in various embodiments, inner box 300 is providedwith an inner box cover or lid 400. The inner box cover or lid may beseparable or partially separable from the inner box. In variousembodiments, inner box cover or lid 400 is sized and/or shaped to coverthe opening, or a portion of the opening, formed by the top of inner box300 sidewalls or cavity. Inner box lid 400 may be formed of any suitablematerial or materials. For example, inner box lid 400 may be formed ofthe same material as the inner box, or may be formed of an alternativematerial or materials. In various embodiments, inner box cover 400includes a pump access panel 411. In various embodiments, pump accesspanel 411 helps improve access to one or more components (e.g. pump)housed within the inner box and/or baffle cavity.

As shown in FIGS. 11 and 15, in various embodiments, inner box lid 400defines or includes a plurality of apertures 410 (e.g. rows ofapertures). In various embodiments, one or more apertures 410 areadapted to removably receive one or more UV lamp or UV-light assembliesor black light assemblies (for ease of reference hereinafter, UV-lightand black light will be referred to as UV-light or like designations,but corresponding descriptions may apply equally to either lightsource). In one or more examples of embodiments, apertures 410 definedby inner box lid 400 are generally aligned (e.g. longitudinally) withthe cells formed between the adjacent electrode structural supportmembers (or electrodes) such that, as shown in FIG. 13, each UV-lightassembly provided in each aperture 410 extends into the cavity or cellbetween or formed at least in part by, facing electrodes or electrodeassemblies. In addition, inner box lid 400 may include one or moreapertures or slots adapted to receive terminals extending from orotherwise electrically coupled to the electrodes.

Referring to FIGS. 13 and 15, apertures 410 defined by or provided inthe inner box lid 400 may receive one or more UV-light sources orassemblies. The UV lights may be oriented (e.g. vertically) between theelectrode structural support members or the photoelectrodes forming eachcell. In one or more examples of embodiments, one or more apertures 410receives a sleeve, casing, or other housing 415 which may help carry orsecure a UV-light source to or relative to lid 400. In variousembodiments, each sleeve, casing, or housing 415 is sealed to lid 400.In one or more further examples, cable glands may be used to help hold(e.g. relative to the inner box lid) the sleeves that house or areadapted to house, at least in part, UV bulbs or UV-light sources. Invarious embodiments, sleeve 415 is formed of any material suitable forthe purposes provided. In one or more examples of embodiments, sleeve415 is a quartz sleeve. In various embodiments, the sleeve may beUV-transparent material, such as, but not limited to, plastic or glass.Alternatively, a UV light source, assembly or bulb may be used orprovided without the sleeve.

In various embodiments, a UV-light bulb is provided into an aperture insleeve 415 and/or inner box lid 410. In various embodiments, a lightsource assembly (e.g. UV light source) is provided. In one or moreexamples of embodiments, a light source assembly includes a lamp or bulband a transparent quartz or fused silica member adapted to house thelamp. In one or more examples of embodiments, the UV light bulb is ahigh irradiance UV light bulb. In one or more further examples ofembodiments, the UV bulb is a germicidal UV bulb with a light emissionin the range of 400 nanometers or less. In various examples ofembodiments, the UV bulb is a germicidal UV bulb with a light emissionin the range of 250 nanometers to 400 nanometers. In variousembodiments, the UV source and/or sleeve extends a distance into thecell in the inner box, such that the UV is exposed to the electrodes,illuminating some or all of the surfaces thereof according to theembodiments described herein. In various embodiments, sleeve 415 extendsat least from inner box lid 400 to at least the bottom of cell 390 (e.g.to or through partition or “false” bottom). This is advantageous in thatthe configuration adds structure and rigidity to the inner box. Oneexample of a distribution of UV lamps is illustrated in FIGS. 11, 13 and15.

In various embodiments, the ultraviolet light has a wavelength in therange of about 185-380 nm. In one or more examples of embodiments, thelamp is a low pressure mercury vapor lamp adapted to emit UV germicidalirradiation at 254 nm wavelength. In one or more alternative examples ofembodiments, a UV bulb with a wavelength of 185 nm may be effectivelyused. In one or more additional examples of embodiments, the lamp isadapted to emit an irradiation intensity in the range of 1-500 mW/cm².The irradiation intensity may vary considerably depending on the type oflamp used. Higher intensities may improve the performance of thephotoelectrocatalytic oxidation (PECO) device. However, the intensitymay be so high that the system is swamped and no further benefit isobtained. That optimum irradiation value or intensity may depend, atleast in part, upon the distance between the lamp and thephotoelectrode.

Various UV light sources, such as germicidal UVC wavelengths (peak at254 nm) and black-light UVA wavelengths (UVA range of 300-400 nm), mayalso be utilized. In one or more examples of embodiments, the optimallight wavelength (e.g. for promoting oxidation) is 305 nm. However,various near-UV wavelengths are also effective. Both types of lamps mayemit radiation at wavelengths that activate photoelectrocatalysis. Thegermicidal UV and black light lamps are widely available and may be usedin commercial applications of the instant PECO device.

The intensity (i.e., irradiance) of UV light at the photoelectrode maybe measured using a photometer available from International LightTechnologies Inc. (Peabody, Mass.), e.g., Model IL 1400A, equipped witha suitable probe. An example irradiation is greater than 3 m Wcm².

UV lamps typically have a “burn-in” period. UV lamps may also have alimited life (e.g., in the range of approximately 6,000 to 10,000hours). UV lamps also typically lose irradiance (e.g., 10 to 40% oftheir initial lamp irradiance) over the lifetime of the lamp. Thus, itmay be important to consider the effectiveness of new and old UV lampsin designing and maintaining oxidation values.

In one or more examples of embodiments, the light source assembly isdisposed exterior to the housing member, and the housing member includesa transparent or translucent member adapted to permit ultraviolet lightemitted from the light source assembly to irradiate the photoelectrode.The device may also function using sunlight instead of, or in additionto, the light source assembly.

Accordingly, a plurality of UV bulbs are inserted into the inner box lidand/or sleeves and may be secured in position. The UV bulbs are furtherconnected to a source of power. In the examples illustrated in theFigures, the bulbs are connected via one or more cables or wires to oneor more ballasts.

A power supply may also be provided in the panel for supplying power tothe UV lamps. The power supply, or an alternative power supply, may alsobe provided in the panel for providing an applied voltage to theelectrodes. In one or more examples of embodiments, increasing theapplied voltage may increase photocurrent and chlorine production. Thepower supply may be an AC or DC power supply and may include a pluralityof outputs. In one or more examples of embodiments, the power supply isa DC power supply. The power supply may be a mountable power supplywhich may be mounted to the panel. Preferably, the power supply is smallin size, is durable or rugged, and provides power sufficient to operatethe plurality of UV-lamps operated by the apparatus and/or to supply theapplied voltage to the electrodes according to the previously describedmethods. Power supplies acceptable for use with the apparatus describedherein are commonly commercially available from companies such asAutomation Direct (Cumming, Ga.) under the RHINO PSS™ trademark, such asa panel mount power supply.

The power supply may be connected to the UV-lamps through electricalconnection with the ballasts. To this end, the power supply may beconnected to the ballasts via one or more terminal blocks. The powersupply or an additional power supply may be connected to the terminalsof the anodes and cathodes described hereinabove via, for example cableconnection to the terminals, for providing a current or charge to theelectrodes as described in the foregoing discussed methods.

Referring again to FIG. 1, in various embodiments, ballasts 419 helpstabilize the current through an electrical load. Each ballast 419 mayprovide a positive resistance or reactance that limits the final currentto an appropriate level. In this way, each ballast 419 may provide forthe proper operation of a negative-resistance device by appearing to bea legitimate, stable resistance in the circuit. Accordingly, in variousembodiments, ballasts 419 are utilized or used to help regulate the flowof current and to provide adequate voltage for the UV-lights or lampsimprove function or otherwise to function properly. Advantageously, invarious embodiments, ballasts 419 help control the amount of currentdrawn, and/or reduce the likelihood of overheating and burnout of thelamps.

In one or more examples of embodiments, ballasts 419 work as follows.When a UV light or lamp is switched on, ballast 419 may supply a highvoltage briefly to establish an arc between two electrodes of the UVbulb or lamp. Once the arc is initiated, ballast 419 may promptly lowerthe voltage and start to regulate the electric current, maintaining asteady light output. The durability of lamps often depends onmaintaining an optimum temperature in the electrodes powering the lamp.Accordingly, in one or more examples of embodiments, ballasts 419 mayutilize or use a circuit (e.g. an independent circuit) that heats thelamp electrodes using a low voltage. This temperature control duringlamp starting and operation elongates lamp life.

The ballasts may also be adaptable ballasts. An adaptable ballast usesmodified circuitry that enables it to operate different lamp types andnumbers of lamps in a range of input voltages. Different manufacturersmay specialize in different types of adaptable ballasts, and ballastssuitable for use with the intended purposes of the PECO device describedherein may be obtained via common commercial means.

According to one or more examples of embodiments as shown in FIG. 1, aplurality of ballasts 419 (e.g. electronic ballasts) adapted for usewith UV lamps are provided for use with the apparatus and system. Invarious embodiments, ballasts 419 are electrically coupled or connectedto internal components (e.g. one or more UV lamps of bulbs) of the PECOunit. In one or more examples of embodiments, ballasts 419 are connectedby wire, or cable, to respective UV lamps carried by the inner box lid,apertures defined therein, and/or sleeves provided therein. In variousembodiments, ballasts 419 are connected to the cable or wire by one ormore terminal blocks which provide a means of connecting the individualelectrical wires for each UV lamp. Any terminal block suitable forconnecting the ballast to the UV lamp may be acceptable for the purposesprovided. Terminal blocks are commonly commercially available fromcompanies such as Automation Direct (Cumming, Ga.).

While specific examples are illustrated including a plurality ofballasts for use with a plurality of UV bulbs, a single ballast may beprovided for use with multiple UV bulbs.

Ballasts 419 and/or any ballast supports may be coupled, connected orsecured to the container, and in particular provided in electricalenclosure 230 coupled to the exterior of container 140. In one or morealternative examples of embodiments, as shown in FIG. 1, ballasts aresecured in electrical enclosure 230 in a row or plurality of rows.Ballasts 419 may be mounted directly to electrical enclosure 230, or maybe mounted to a plate which is secured to container 140 or to electricalenclosure 230. In various embodiments, the ballasts are provided in astacked arrangement in which a first plurality of ballasts arepositioned on a ballast support above a second plurality of ballasts.

As shown in FIGS. 16 and 17, in various embodiments, one or moreelectrodes 420/430 are provided on, and/or, or may be supported by,electrode structural support member 370. In various embodiments,electrodes 420/430 are supported on one face or both opposing faces ofvarious electrode structural support members 370. For example, aphotoelectrode (e.g. anode) 420, counter electrode (e.g. cathode) 430,and separator 440 may be coupled to electrode structural support member370 by an attachment mechanism, such as but not limited to, a plastic ornon-conductive screw or rivet. The electrodes 420/430 may extend thedepth of the inner box cavity, or a portion thereof.

In various embodiments, the electrodes 420/430 include one or morephotoelectrodes (e.g. anodes) 420, and one or more counterelectrodes(e.g. cathodes) 430. As can be seen by reference to the Figures, invarious embodiments, each electrode 420/430 is formed of a sheet ofmaterial, or plurality of (e.g., interconnected or adjoining) sheets ofmaterial. In one or more examples of embodiments, the distance betweenelectrodes is minimized while preventing shorting between thephotoelectrode (e.g. anode) 420 and a counterelectrode (e.g. cathode)430. As can be seen in FIGS. 16 & 17, in various embodiments, thephotoelectrode (e.g. anode) 420 and counter electrode (e.g. cathode) 430are separated by a separator 440. Separator 440 may be used or otherwiseprovided to prevent shorting. In one or more examples of embodiments,photoelectrode (e.g. anode) 420 and counterelectrode (e.g. cathode) 430are separated by a plastic mesh separator 440, although alternativeseparators (e.g. those accomplishing or tending to accomplish the sameor similar purposes) may be acceptable for use with the device andsystem described herein. In the illustrated examples, and exampleembodiments, counterelectrode (e.g. cathode) 430 is placed or otherwiseprovided “behind” the photoelectrode (e.g. anode) 420 relative to a UVlight source (not shown) (i.e., between electrode structure supportmember 270 and photoelectrode 420). In various embodiments,photoelectrode or anode 420 is corrugated and/or defined or includes aplurality of holes punched therein. As a result of the holes, thepositioning, etc., the photoelectrode may help create turbulence influid flowing in the system. Additionally, one or more holes may allowoxidants generated or produced on or near a surface of photoelectrode420 to more rapidly and effectively make their way into or otherwisereach or react with the fluid (e.g., aqueous solution) and/orcontaminants therein.

Positioning of the photoelectrode and counterelectrode in relation tothe relative surface area may be of importance in one or more examplesof embodiments. For instance, a smaller surface area photoelectrodepositioned relatively closer to UV light may generate more photocurrentand chlorine than a larger surface area photoelectrode positionedrelatively farther from UV light. Centering of the anode may also behelpful in optimizing or maximizing productivity. Likewise, multiplephotoelectrodes may be utilized to improve photocurrent, oxidation, andchlorine generation.

Referring to FIG. 17, in various embodiments, terminals 450/460 arerespectively electrically coupled (e.g. attached) tocounterelectrode/cathode 430 and photoelectrode/anode 420, forming arespective positive terminal 450 and negative terminal 460. Terminals450/460 are formed of a conductive material, such as a conductive metal.In various embodiments, terminals 450/460 of respective cathodes andanodes, which are spaced by a separator, are provided or positioned inclose proximity to each other. In various embodiments, terminals 450/460include a portion that extends beyond or above counterelectrode (e.g.cathode) 430 and photoelectrode (e.g. anode) 420, and further extendsbeyond or above an upper edge 470 of inner box or structure 300. One ormore terminals may define or be provided with an aperture for ease ofconnection or coupling of the terminal to a wire, electrical cable orthe like.

In one or more examples of alternative embodiments, the plurality ofstructural support members having the electrodes thereon may be providedin a cascading tray system, which may comprise flat trays stacked one ontop of another, with UV light sources positioned between said trays,such that water cascades from one level to the next in alternatingdirections.

In various embodiments, photoelectrode 420 includes a conductive supportmember and a film member. In one or more examples of embodiments, theconductive support member is constructed from metal (e.g. titanium). Invarious embodiments, the film member is nanoporous and includes a thinlayer (e.g., 200-500 nm) of a titanium dioxide (TiO₂) that is providedor adapted to function as a photocatalyst. In various examples ofembodiments, the film member has an average thickness in the range of1-2000 nanometers. In one or more examples of embodiments, the filmmember has an average thickness in the range of 5 to 500 nanometers.

In various embodiments, the film member is provided on (e.g., coated onor adhered to) the conductive support member. In various embodiments,the film member has a median pore diameter in the range of 0.1-500nanometers constructed from TiO₂ nanoparticles. In one or more examplesof embodiments, the median pore diameter of the film member is in therange of 0.3-25 nanometers. In other examples of embodiments, the medianpore diameter of the film member is in the range of 0.3-10 nanometers.

In various examples of embodiments, the film member is constructed froma stable, dispersed suspension comprising TiO₂ nanoparticles having amedian primary particle diameter in the range of 1-50 nanometers. Thenanoporous film may also be deposited by other methods, such as plasma,chemical vapor deposition or electrochemical oxidation. In one or moreexamples of embodiments, the TiO₂ nanoparticles have a median primaryparticle diameter in the range of 0.3-5 nanometers.

In various embodiments, the film member is constructed from a stable,dispersed suspension including a doping agent. Examples of suitabledoping agents include, but are not limited to, Pt, Ni, Au, V, Sc, Y, Nb,Ta, Fe, Mn, Co, Ru, Rh, P, N and/or carbon.

In various examples of embodiments, the nanoporous film member isconstructed by applying a stable, dispersed suspension having TiO₂nanoparticles suspended therein. In various embodiments, the TiO₂nanoparticles are sintered at a temperature in the range of 300 deg C.to 1000 deg C. for 0.5 to 24 hours. Example photoelectrodes may beprepared by coating Ti metal foil. One example of suitable Ti metal foilincludes 15 cm×15 cm×0.050 mm thickness and 99.6+% (by weight) pure Timetal foil commercially available from Goodfellow Corp. (Oakdale, Pa.)with a titania-based metal oxide. In various embodiments, the Ti metalfoil is cleaned with a detergent solution, rinsed with deionized water,rinsed with acetone, and/or heat-treated at 350 deg C. for 4 hoursproviding an annealed Ti foil Annealing may also be conducted at highertemperatures such as 500 deg C.

Following cleaning and/or pretreatment, in various embodiments, themetal foil may be dip-coated. For example, the metal foil may bedip-coated three to five times with an aqueous suspension of titania ata withdrawal rate of ˜3.0 mm/sec. After each application of coating, invarious embodiments, the coated foil is air dried for about 10-15 minand then heated in an oven at 70 deg C. to 100 deg C. for about 45 min.After applying a final coating, in various embodiments, the coated foilis sintered at 300-500 deg C. (e.g., 300 deg C., 400 deg C. or 500 degC.) for 4 hours at a 3 deg C./min ramp rate. The Ti foil may be dippedinto suspensions of titania synthesized using methods disclosed in U.S.patent application Ser. Nos. 11/932,741 and 11/932,519, each of which isincorporated herein by reference in its entirety. In variousembodiments, the optimized withdrawal speed is around 21.5 cm min⁻¹.

Titanium foil is stable and may also be used to make photoelectrodes.

In addition, in one or more examples of embodiments of thephotoelectrode, the stable, dispersed suspension is made by reactingtitanium isopropoxide and nitric acid in the presence of ultrapure wateror water purified by reverse osmosis, ion exchange, and one or morecarbon columns. In various embodiments, the conductive support member isannealed titanium foil. Other conductive supports may be employed, suchas conductive carbon or glass. In various other embodiments, thephotoelectrode is constructed from an anatase polymorph of Ti or arutile polymorph of Ti. In one or more examples of embodiments of thephotoelectrode, the rutile polymorph of Ti is constructed by heating ananatase polymorph of Ti at a temperature in the range of 300 deg C. to1000 deg C. for a sufficient time. In one or more examples ofembodiments of the photoelectrode, the anatase polymorph of Ti is heatedat 500 deg C. to 600 deg C. to produce the rutile polymorph of Ti.

In various embodiments, after the titanium support is provided with alayer or film of TiO₂, the composite electrode is air-heated at a hightemperature, giving the nanoporous TiO₂ film a crystalline structure dueto thermal oxidation. It is believed that the instant titania, whenheated at 500 deg C., converts to a crystalline rutile polymorphstructure. It is further believed that the instant TiO₂ heated at 300deg C. converts to a crystalline anatase polymorph structure. In somePECO applications, rutile TiO₂ has substantially higher catalyticactivity than the anatase TiO₂. Rutile TiO₂ may also have substantiallyhigher catalytic activity with respect to certain contaminant such asammonia.

In various embodiments, photoelectrode 420 is modified (e.g. to improveperformance). In various embodiments, such modifications include holesor perforations made or provided in photoelectrode 420, conductivesupport member or foil. In various embodiments, the holes orperforations are made at regular intervals (e.g., 0.5 to 3 cm spacingbetween the holes). In various embodiments, such modifications alsoinclude corrugating or otherwise modifying the photoelectrode,conductive support member or foil to produce a wave-like pattern (e.g.,regular wave-like pattern) on the foil surface. In various embodiments,the height of a corrugation “wave” is 1-5 mm. For example, in variousembodiments, corrugating the foil twice at right angles to each otherproduces a unique cross-hatched pattern on the foil surface. In one ormore examples of embodiments, Ti mesh (e.g., 40×40 twill weave, 60×60dutch weave, etc.) may be used for making a photoelectrode (e.g.,anode).

Modifications of the photoelectrode may also include variousmicrofeatures and/or microstructures. Accordingly to variousembodiments, the modifications of the photoelectrode, conductive supportmember or foil may also include various microfeatures and/ormicrostructures that increase the relative surface area of thephotoelectrode and/or increase or promote turbulence about thephotoelectrode. For example, according to various embodiments, suchmicrofeatures and/or microstructures include those that are disclosed inU.S. Patent Publication Nos. 20100319183 and 20110089604, each of whichis incorporated herein by reference in its entirety, or suchmicrofeatures and/or microstructures that are provided commercially fromHoowaki, LLC (Pendleton, S.C.). In various embodiments, themicrofeatures may include microholes.

In one or more examples of embodiments, counterelectrode or cathode 430is constructed from or includes Al, Pt, Ti, Ni, Au, stainless steel,carbon and/or another conductive metal. In one or more examples ofembodiments, counterelectrode 430 is in the form of a foil. However, thecounterelectrode may alternatively be in the form or shape of a wire,plate or cylinder.

One or more power supplies, in one or more examples of embodiments, maybe connected to a power switch for activating or deactivating the supplyof power. In one or more further examples of embodiments, a powersupply, UV lamps, and or electrodes, may be connected to or incommunication with programmable logic controller or other control orcomputer for selectively distributing power to the UV lamps and/or tothe electrodes, including anodes and cathodes described herein.

In various embodiments, the PECO device may also include a potentiostat,and a reference electrode in electrical communication with thepotentiostat. In one or more examples of embodiments, the device furthercomprises a reference electrode and a voltage control device, such as apotentiostat, adapted to maintain a constant voltage or constant currentbetween the reference electrode and the photoelectrode. In variousembodiments, the housing member is adapted to house the referenceelectrode.

In one or more examples of embodiments, the device further comprises asemi-micro saline bridge member connecting the potentiostat andreference electrode, whereby the housing member is adapted to house thesaline bridge.

In one or more examples of embodiments, the reference electrode isconstructed from silver and is in the shape of a wire.

In one or more examples of embodiments, the potential on thephotoelectrode is held constant relative to a saturated calomelreference electrode by potentiostat, such as EG&G Model 6310. In variousembodiments, the potentiostat is connected to the reference electrodethrough a semi-micro saline bridge, such as available from EG&G, ModelK0065. The saline bridge may be disposed inside the reactor close tophotoelectrode. The current passing through the PECO device may bemeasured.

In various embodiments, the instant potentiostat is a variable currentsource that can measure a voltage between two electrodes. Thepotentiostat can perform a wide variety of electrochemical functions,but the two example functional modes are constant current and constantvoltage. In constant current mode, the potentiostat supplies a userspecified or predetermined current to the electrodes. In constantvoltage mode, it supplies current to the electrodes while monitoring thevoltage. It can then continually adjust the current such that thevoltage will remain constant at a user specified value. A potentiostatcan also be configured to supply pulses.

A temperature probe(s) may also be provided in one or more examples ofembodiments. The temperature probe(s) may be positioned in the containerand/or in the inner box. The temperature probe may monitor thetemperature in the container or in the box or in the fluid within therespective container or box and communicate that temperature reading.Further the temperature probe may be in communication with a shut-offswitch or valve which is adapted to shut the system down upon reaching apredetermined temperature.

A fluid level sensor(s) may also be provided which may communicate afluid level reading. The fluid level sensor(s) may be positioned in thecontainer and/or in the inner box. Further the fluid level sensor may bein communication with a shut-off switch or valve which is adapted toshut off the intake of fluid or engage or increase the outflow of fluidfrom the container upon reaching a predetermined fluid value.

In one or more examples of embodiments, the device includes a carbonfilter adapted to filter chlorine from the water. In variousembodiments, the device includes a computer adapted to send one or morecontrolled signals to the existing power supplies to pulse the voltageand current.

In operation of the foregoing example embodiment, contaminated fluid,such as contaminated water, may be pumped or otherwise directed into thecontainer and circulated into and through the series of cells, which maybe in the inner box. In various embodiments, the contaminated waterflows through the series of cells, from one cell to the next, in aserpentine or undulating pattern and is processed via the poweredelectrodes and light assemblies according to the methods describedherein. The maximum fluid level in the container and/or the inner boxmay be just below the upper edge of the respective container or box,although alternative fluid levels would not depart from the overallscope of the present invention. The water may be circulated and/orrecirculated within the inner box or container. Multiple units, orreactors, may be connected and operated in series, which may result inincreased space and time for contaminated fluid in the reactor(s). Uponcompletion of processing, in various embodiments, the water exits theinner box and container ready for use.

In various embodiments, in operation, the TiO₂ photocatalyst isilluminated with light having sufficient near UV energy to generatereactive electrons and holes promoting oxidation of compounds on theanode surface.

Any temperature of liquid water is suitable for use with the instantPECO device. In various embodiments, the water is sufficiently low inturbidity to permit sufficient UV light to illuminate thephotoelectrode.

In various embodiments, photocatalytic efficiency is improved byapplying a potential (i.e., bias) across the photoelectrode andcounterelectrode. Applying a potential may decrease the recombinationrate of photogenerated electrons and holes. In various embodiments, aneffective voltage range applied may be in the range of −1 V to +15 V. Invarious embodiments, an electrical power source is adapted to apply anelectrical potential in the range of 4 V to 12 V across thephotoelectrode and counterelectrode. In various embodiments, theelectrical power source is adapted to generate an electrical potentialin the range of 1.2 V to 3.5 V across the photoelectrode andcounterelectrode (or, 0 to 2.3 V vs. the reference electrode).

For various applications, including, for example fracking fluid orhigh-salinity applications, it may be desirable to reverse (e.g.,periodically or intermittently) the potential, bias, polarity and/orcurrent applied to or between the photoelectrode and thecounterelectrode (e.g., to clean the photoelectrode and/orcounterelectrode, or to otherwise improve the performance of thephotoelectrode, counterelectrode, or PECO device). In variousembodiments, by reversing the potential, bias, polarity and/or current,the photoelectrode is changed (e.g. from an anode) into a cathode andthe counterelectrode is changed (e.g. from a cathode) into an anode.

For example, in various embodiments, initially positive voltage iselectrically connected to a positive charge electrode and negativevoltage is electrically connected to a negative charge electrode. Aftera first period of time, the positive voltage is electrically connectedto the negative charge electrode and the negative voltage iselectrically connected to the positive charge electrode. After a secondperiod of time, the positive voltage is electrically connected back tothe positive charge electrode and the negative voltage is electricallyconnected back to the negative charge electrode. This reversal processmay be repeated as necessary or desired.

The length of the first period of time and the second period of time maybe the same. In various embodiments, however, the length of the firstperiod of time and the second period of time are different. In variousembodiments, the first period of time is longer than the second periodof time.

The length of the first and second periods of time depends on a varietyof factors including salinity, application, voltage, etc. For example,fracking fluid or high salinity fluid applications may requirerelatively more frequent reversal of potential, bias, polarity and/orcurrent compared to fresh water applications. In various embodiments,the lengths of the first period of time relative to the second period oftime may be in a ratio of from 3:1 to 50:1, and in one or more furtherembodiments from 3:1 to 25:1, and in one or more further embodimentsfrom 3:1 to 7:1. For example, in various embodiments, the first periodof time and second period of time is about 5 minutes to about 1 minute.Fresh water applications may require relatively less frequent reversalof potential, bias, polarity and/or current, and the lengths of thefirst period of time relative to the second period of time may be in aratio of from 100:1 to 10:1. For example, in various embodiments, thefirst period of time and second period of time is about 60 minutes to arange of about 1 minute to about 5 minutes.

In various embodiments, the voltage applied between the photoelectrodeand counterelectrode may not change during the first period of time ofnormal potential and during the second period of time of reversepotential. For example, in various embodiments (e.g, where thephotoelectrode includes titanium and the apparatus and/or method areadapted for treatment of fracking or other high salinity solution) thevoltage applied during the first period of time may be less than 9V(e.g., about 7.5V) and the voltage applied during the second period oftime may be less than 9V (e.g., about 7.5V). In other variousembodiments (e.g, where the photoelectrode includes titanium and theapparatus and/or method are adapted for treatment of fresh water) thevoltage applied during the first period of time may be greater than 9V(e.g., about 12V) and the voltage applied during the second period oftime may be greater than 9V (e.g., about 12V).

Maintaining the voltage in the first period of time and the secondperiod of time may help to un-foul the photoelectrode to help make itmore effective for removing contaminants through photoelectrocatalyticoxidation during the first period of time. However, maintaining thevoltage under 9V in each period of time may cause a momentarydisturbance in the removal of contaminants during the second period oftime. For a variety of reasons, (e.g., to help minimize any suchdisturbance and/or to help cause electroprecipitation and/orelectrocoagulation), in various embodiments, it may be advantageous toapply higher voltages (e.g. voltages greater than 9V) during the firstperiod of time and second period of time. In various embodiments,applying higher voltages helps to promote an electrochemical processsuch as electroprecipitation and/or electrocoagulation during the secondperiod of time, which process can help minimize any disturbance inremoval of contaminants during the second period of time as well asoffer advantages and benefits of such a process.

In various embodiments, the voltage is adjusted to control the rate ofdissolution of the electrode. In various examples of embodiments, thevoltage applied during the first period of time may be more than 9V(e.g., about 12V) and the voltage applied during the second period oftime may be more than 9V (e.g., about 12V). Higher voltages may helpoptimize the effectiveness of the PECO device in certain ways. Highervoltages may also lead to electroprecipitation or electrocoagulation ofcontaminants within or from the fluid. However, such higher voltages mayalso lead to anodic dissolution such as pitting and other degradation ofthe photoelectrode and/or counterelectrode, which may necessitate morefrequent servicing of the PECO device (e.g. replacement of thephotoelectrode (e.g., the foil) and counterelectrode).

In various embodiments, it may be advantageous (e.g., to help limit anyanodic dissolution, or pitting or other degradation of thephotoelectrode) to apply relatively lower voltages during the firstperiod of time and relatively higher voltages during the second periodof time. In various embodiments, e.g., in a fracking fluid applicationusing a photoelectrode and a counterelectrode including titanium, thevoltage applied during the first period of time may be less than 9V(e.g., about 7.5V) and the voltage applied during the second period oftime may be more than 9V (e.g., about 12V for fracking fluid or highersalinity applications, to about 14V for fresh water applications). Invarious embodiments, during application of relatively lower voltageduring the first period of time, contaminants are degraded (or theremoval of contaminants is promoted) by photoelectrocatalytic oxidation,and during application of a relatively higher voltage during the secondperiod of time, contaminants are degraded (or the removal ofcontaminants is promoted) by an electrochemical process such aselectroprecipitation and/or electrocoagulation.

In various embodiments, during the second period of time, thecounterelectrode or sacrificial electrode of titanium is dissolved atleast in part by anodic dissolution. It is believed that a range ofcoagulant species of hydroxides are formed (e.g. by electrolyticoxidation of the sacrificial counterelectrode), which hydroxides helpdestabilize and coagulate the suspended particles or precipitate and/oradsorb dissolved contaminants.

In various embodiments, it is advantageous to apply relatively highervoltages during the first period of time and relatively lower voltagesduring the second period of time. In various embodiments, the voltageapplied during the first period of time is more than 9V (e.g., about12V) and the voltage applied during the second period of time is lessthan 9V (e.g., about 7.5V).

In various embodiments, the main reaction occurring at thecounterelectrodes or sacrificial electrodes during the second period oftime (e.g., during polarity reversal) is dissolution:

Tl_((s))→Ti⁴⁺+4e ⁻

In addition, water is electrolyzed at the counterelectrode (orsacrificial electrode) and photoelectrode:

2H₂O+2e ⁻→H_(2(g))+2OH⁻(cathodic reaction)

2H₂O→4H⁺+O_(2(g))+4e ⁻(anodic reaction)

In various embodiments, electrochemical reduction of metal cations(Me^(n+)) occurs at the photoelectrode surface:

Me^(n+) +ne ⁻ →nMe^(o)

Higher oxidized metal compounds (e.g., Cr(VI)) may also be reduced (e.g.to Cr(III)) about the photoelectrode:

Cr₂O₇ ²⁻+6e ⁻+7H₂O→2Cr³⁺+14OH⁻

In various embodiments, hydroxide ions formed at the photoelectrodeincrease the pH of the solution which induces precipitation of metalions as corresponding hydroxides and co-precipitation with metal (e.g.Ti) hydroxides:

Me^(n+) +nOH⁻→Me(OH)_(n(s))

In addition, anodic metal ions and hydroxide ions generated react in thesolution to form various hydroxides and built up polymers:

Ti⁴⁺+4OH⁻→Ti(OH)_(4(s))

nTi(OH)_(4(s)) ⁻→Ti_(n)(OH)_(4n(s))

However, depending on the pH of the solution other ionic species mayalso be present. The suspended titanium hydroxides can help removepollutants from the solution by sorption, co-precipitation orelectrostatic attraction, and coagulation.

For a particular electrical current flow in an electrolytic cell, themass of metal (e.g. Ti) theoretically dissolved from thecounterelectrode or sacrificial electrode is quantified by Faraday's law

$m = \frac{ItM}{zF}$

where m is the amount of counterelectrode or sacrificial electrodematerial dissolved (g), I the current (A), t the electrolysis time (s),M the specific molecular weight (g mol⁻¹), z the number of electronsinvolved in the reaction and F is the Faraday's constant (96485.34 Asmol⁻¹). The mass of evolved hydrogen and formed hydroxyl ions may alsobe calculated.

In various embodiments, it may be advantageous (e.g., to help limit anyanodic dissolution, or pitting or other degradation of thephotoelectrode) to apply certain voltages (e.g., relatively highervoltages) during the first period of time and different voltages (e.g.,relatively lower voltages) during the second period of time. In variousembodiments (e.g., in a fracking fluid application using acounterelectrode including aluminum), the voltage applied during thefirst period of time may be about 6V to 9V (e.g., about 7.5V) and thevoltage applied during the second period of time may be about 0.6V-12V.In various embodiments, during application of relatively higher voltageduring the first period of time, contaminants are degraded (or theremoval of contaminants is promoted) by photoelectrocatalytic oxidation,and during application of a relatively lower voltage during the secondperiod of time, contaminants are degraded (or the removal ofcontaminants is promoted) by and electrochemical process suchelectroprecipitation or electrocoagulation.

In various embodiments, during the second period of time, an aluminumcounterelectrode or sacrificial electrode is dissolved at least in partby anodic dissolution. It is believed that a range of coagulant speciesof hydroxides are formed (e.g. by electrolytic oxidation of thesacrificial counterelectrode), which hydroxides help destabilize andcoagulate the suspended particles or precipitate and/or adsorb dissolvedcontaminants.

In various embodiments, the main reaction occurring at thecounterelectrodes or sacrificial electrodes during the second period oftime (e.g., during polarity reversal) is dissolution:

Al_((s))→Al³⁺+3e ⁻

Additionally, water is electrolyzed at the counterelectrode (orsacrificial electrode) and photoelectrode:

2H₂O+2e ⁻→H_(2(g))+2OH⁻(cathodic reaction)

2H₂O→4H⁺+O_(2(g))+4e ⁻(anodic reaction)

In various embodiments, electrochemical reduction of metal cations(Me^(n+)) occurs at the photoelectrode surface:

Me^(n+) +ne ⁻ →nMe^(o)

Higher oxidized metal compounds (e.g., Cr(VI)) may also be reduced (e.g.to Cr(III)) about the photoelectrode:

Cr₂O₇ ²⁻+6e ⁻+7H₂O→2Cr³⁺+14OH⁻

In various embodiments, hydroxide ions formed at the photoelectrodeincrease the pH of the solution which induces precipitation of metalions as corresponding hydroxides and co-precipitation with metal (e.g.Al) hydroxides:

Me^(n+) +nOH⁻→Me(OH)_(n(s))

In addition, anodic metal ions and hydroxide ions generated react in thesolution to form various hydroxides and built up polymers:

Al³⁺+3OH⁻→Al(OH)_(3(s))

nAl(OH)_(3(s)) ⁻→Al_(n)(OH)_(3(s))

However, depending on the pH of the solution other ionic species, suchas dissolved Al(OH)²⁺, Al₂(OH)₂ ⁴⁺ and Al(OH)₄ ⁻ hydroxo complexes mayalso be present. The suspended aluminum hydroxides can help removepollutants from the solution by sorption, co-precipitation orelectrostatic attraction, and coagulation.

For a particular electrical current flow in an electrolytic cell, themass of metal (e.g. Al) theoretically dissolved from thecounterelectrode or sacrificial electrode is quantified by Faraday's law

$m = \frac{ItM}{zF}$

where m is the amount of counterelectrode or sacrificial electrodematerial dissolved (g), I the current (A), t the electrolysis time (s),M the specific molecular weight (g mol⁻¹), z the number of electronsinvolved in the reaction and F is the Faraday's constant (96485.34 Asmol⁻¹). The mass of evolved hydrogen and formed hydroxyl ions may alsobe calculated.

The present invention, in one or more examples of embodiments, isdirected to methods of treating an aqueous solution having one or morecontaminants therein to help remove or reduce the amounts ofcontaminants. In various embodiments, the method includes providing anaqueous solution comprising at least one contaminant selected from thegroup consisting of an organism, an organic chemical, an inorganicchemical, and combinations thereof and exposing the aqueous solution tophotoelectrocatalytic oxidization.

In one example of an application of the device described herein, thedevice uses photoelectrocatalysis as a treatment method for frackingfluid. While typically described herein as reducing or removingcontaminants from fracking fluid, it should be understood by one skilledin the art that photoelectrocatalysis of other contaminants can beperformed similarly using the photoelectrocatalytic oxidation or PECOdevice.

Generally, the method for reducing amount of contaminants in solution orfluid described includes introducing the solution into a housing orcontainer or cell including: a UV light; a photoelectrode, wherein thephotoelectrode comprises an anatase polymorph of titanium, a rutilepolymorph of titanium, or a nanoporous film of titanium dioxide; and acathode. The photoelectrode is irradiated with UV light, and a firstpotential is applied to the photoelectrode and counterelectrode for afirst period of time. A second potential is applied to thephotoelectrode and counterelectrode for a second period of time. As aresult, the contaminant amount in solution is reduced.

In various embodiments, one or more contaminants are oxidized by a freeradical produced by a photoelectrode, and wherein one or morecontaminants are altered electrochemically (e.g. by electroprecipitationor electrocoagulation). In various embodiments, one or more contaminantsare oxidized by a chlorine atom produced by a photoelectrode. In variousembodiments, one or more contaminants are altered electrochemically(e.g. by electroprecipitation or electrocoagulation).

The instant apparatus and methods utilizes photoelectrocatalyticoxidation, whereby a photocatalytic anode is combined with acounterelectrode to form an electrolytic cell. When the instant anode isilluminated by UV light, its surface becomes highly oxidative. Bycontrolling variables including, without limitation, chlorideconcentration, light intensity, pH and applied potential, the irradiatedand biased TiO₂ composite photoelectrode selectively oxidizescontaminants that come into contact with the surface, forming lessharmful gas or other compounds. Application of a potential to thephotoelectrode provides further control over the oxidation products.Periodic or intermittent reversal of the potential helps further removeor reduce the amount of contaminants.

The foregoing apparatus and method provides various advantages. Thedevice may be provided in a portable container, permitting on-site wateror fluid decontamination. Further, the device is modular in design andcan be easily increased or decreased in size as needed. The device isalso easy to fabricate and includes electrical connections which areeasy to make. UV lights illuminate anodes on both sides (e.g. internalsides) of the individual cells, advantageously and effectively doublinganode surface area illuminated by each bulb, as well as reducing thenumber of UV bulbs required and the corresponding power and electricalconnections required to operate the bulbs. In the apparatus described,the cathode is positioned behind the anode and away from the scouringaction of water flow, reducing or limiting scale accumulation.Additionally, the spacer positioned between the cathode and anodereduces shorting caused by contact of the cathode and anode. These andother advantages are apparent from the foregoing description andassociated Figures.

As utilized herein, the terms “approximately,” “about,” “substantially”,and similar terms are intended to have a broad meaning in harmony withthe common and accepted usage by those of ordinary skill in the art towhich the subject matter of this disclosure pertains. It should beunderstood by those of skill in the art who review this disclosure thatthese terms are intended to allow a description of certain featuresdescribed and claimed without restricting the scope of these features tothe precise numerical ranges provided. Accordingly, these terms shouldbe interpreted as indicating that insubstantial or inconsequentialmodifications or alterations of the subject matter described and claimedare considered to be within the scope of the invention as recited in theappended claims.

It should be noted that references to relative positions (e.g., “top”and “bottom”) in this description are merely used to identify variouselements as are oriented in the Figures. It should be recognized thatthe orientation of particular components may vary greatly depending onthe application in which they are used.

For the purpose of this disclosure, the term “coupled” means the joiningof two members directly or indirectly to one another. Such joining maybe stationary in nature or moveable in nature. Such joining may beachieved with the two members or the two members and any additionalintermediate members being integrally formed as a single unitary bodywith one another or with the two members or the two members and anyadditional intermediate members being attached to one another. Suchjoining may be permanent in nature or may be removable or releasable innature.

It is also important to note that the construction and arrangement ofthe system, methods, and devices as shown in the various examples ofembodiments is illustrative only. Although only a few embodiments havebeen described in detail in this disclosure, those skilled in the artwho review this disclosure will readily appreciate that manymodifications are possible (e.g., variations in sizes, dimensions,structures, shapes and proportions of the various elements, values ofparameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter recited. For example,elements shown as integrally formed may be constructed of multiple partsor elements show as multiple parts may be integrally formed, theoperation of the interfaces may be reversed or otherwise varied, thelength or width of the structures and/or members or connector or otherelements of the system may be varied, the nature or number of adjustmentpositions provided between the elements may be varied (e.g. byvariations in the number of engagement slots or size of the engagementslots or type of engagement). The order or sequence of any process ormethod steps may be varied or re-sequenced according to alternativeembodiments. Other substitutions, modifications, changes and omissionsmay be made in the design, operating conditions and arrangement of thevarious examples of embodiments without departing from the spirit orscope of the present inventions.

While this invention has been described in conjunction with the examplesof embodiments outlined above, various alternatives, modifications,variations, improvements and/or substantial equivalents, whether knownor that are or may be presently foreseen, may become apparent to thosehaving at least ordinary skill in the art. Accordingly, the examples ofembodiments of the invention, as set forth above, are intended to beillustrative, not limiting. Various changes may be made withoutdeparting from the spirit or scope of the invention. Therefore, theinvention is intended to embrace all known or earlier developedalternatives, modifications, variations, improvements and/or substantialequivalents.

We claim:
 1. An apparatus for removing or reducing the level ofcontaminants in a solution comprising: a structure, the structurecomprising a first sidewall and a second sidewall, a structure cover,and spaced-apart electrode structural support members extending betweenthe first sidewall and the second sidewall; the structure cover definingapertures with sleeves provided therein that extend into a space betweenthe spaced-apart electrode structural support members; the spaced-apartelectrode structural support members each having at least onephotoelectrode and at least one counterelectrode provided thereon;wherein the photoelectrode comprises a primarily titanium foil supportwith a layer of titanium dioxide provided thereon; and wherein thephotoelectrode and counterelectrode are each coupled to a respectiveterminal adapted to be electrically coupled to a power supply.
 2. Theapparatus of claim 1, wherein each of the spaced-apart electrodestructural support members defines at least one aperture near an edge ofthe electrode structural support member.
 3. The apparatus of claim 2,wherein at least two spaced-apart electrode structural support membersare provided such that respective apertures of the spaced-apartelectrode structural support members are not aligned.
 4. The apparatusof claim 1, wherein a UV light source is provided in each sleeve.
 5. Theapparatus of claim 4, wherein at least one of the UV light sources iselectrically coupled to a ballast.
 6. The apparatus of claim 1, whereinmultiple photoelectrodes are provided on at least one of thespaced-apart electrode structural support members.
 7. The apparatus ofclaim 6, wherein multiple counterelectrodes are provided on at least oneof the spaced-apart electrode structural support members.
 8. Anapparatus for removing or reducing the level of contaminants in asolution comprising: a structure comprising a sidewall, and a structurecover and spaced-apart electrode structural support members extendingfrom the sidewall to form a cell between the spaced-apart electrodestructural support members; the structure cover defining apertures withsleeves provided therein that extend from the structure cover into thecell formed between the spaced-apart electrode structural supportmembers; the spaced-apart electrode structural support members eachhaving a photoelectrode and counterelectrode provided thereon with aseparator provided between the photoelectrode and counterelectrode;wherein the photoelectrode comprises a primarily titanium foil supportwith a layer of titanium dioxide provided thereon; and wherein thephotoelectrode and counterelectrode are each coupled to a terminaladapted to be electrically coupled to a power supply.
 9. The apparatusof claim 8, wherein each spaced-apart electrode structural supportmember defines at least one aperture near an edge of the electrodestructural support member.
 10. The apparatus of claim 9, wherein thespaced-apart electrode structural support members are provided such thatrespective apertures of the spaced-apart electrode structural supportmembers are not aligned.
 11. The apparatus of claim 8, wherein a UVlight source is provided in each sleeve.
 12. The apparatus of claim 11,wherein at least one of the UV light sources is electrically coupled toa ballast.
 13. The apparatus of claim 8, wherein multiplephotoelectrodes are provided on at least one of the spaced-apartelectrode structural support members.
 14. The apparatus of claim 13,wherein multiple counterelectrodes are provided on at least one of thespaced-apart electrode structural support members.
 15. An apparatus forremoving or reducing the level of contaminants in a solution comprising:a structure, the structure comprising a first set of opposing memberscoupled to a second set of opposing members, and spaced-apart electrodestructural support members extending between the first and second set ofopposing members; the spaced-apart electrode structural support memberseach having a photoelectrode and counterelectrode provided thereon;wherein each of the opposing members of the first set of opposingmembers define apertures with sleeves provided therein, which sleevesextend at least from one opposing member of the first set of opposingstructure members to another opposing member of the first set ofopposing members into a space between the spaced-apart electrodestructural support members; wherein the photoelectrode comprises aprimarily titanium foil support with a layer of titanium dioxideprovided thereon; and wherein the photoelectrode and counterelectrodeare each coupled to a terminal adapted to be electrically coupled to apower supply.
 16. The apparatus of claim 15, wherein each spaced-apartelectrode structural support member defines at least one aperture nearan edge of the spaced-apart electrode structural support member.
 17. Theapparatus of claim 16, wherein at least two spaced-apart electrodestructural support members are provided such that apertures of thespaced-apart electrode structural support members are not aligned. 18.The apparatus of claim 15, wherein a UV light source is provided in eachsleeve.
 19. The apparatus of claim 15, wherein multiple photoelectrodesare provided on at least one of the spaced-apart electrode structuralsupport members.
 20. The apparatus of claim 19, wherein multiplecounterelectrodes are provided on at least one of the spaced-apartelectrode structural support members.